Question 1119798
<br>
{{{x^2+2x(5-x)+(5-x)^2}}}<br>
The given expression is of the form<br>
{{{A^2+2AB+B^2}}}<br>
which is equivalent to<br>
{{{(A+B)^2}}}<br>
So the given expression is equivalent to<br>
{{{(x+(5-x))^2 = 5^2 = 25}}}